Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!

Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.

I decided to replace my timing belt the other day after noticing some chewing going on with the top of the belt. One of the belt guides was just barely touching which was wearing that area. I also decided to replace the belt tentioner at the same time. However, I stripped a few threads and decided to get a longer bolt to compensate on the tentioner. Well apparently the bolt was not the correct grade because three days later the POS broke, leaving me stranded on the interstate. No more bolts from Home Depot

When that happened, I immediately pushed the clutch in when the engine lost power. I knew that losing power couldn't have been good CEL, dash lights and all. I looked under the hood and my greatest fear was confirmed. It was of course the tentioner that had let go and my poor belt was just hanging on to the pass side cams.

As luck would have it, I repaired the threads with a helicoil and put everything back together over the weekend. The damned thing is in perfect running condition. I just did a compression check tonight and each cylinder is the same as before. Really odd!

So I thought these were interference engines?? I've got zero damage. I was thinking that because my pistons have deep valve pockets that might be it, but on the other hand it's the Int valve to Exh valve contact is what's the problem.

Well, if you don't have any problems then you are super lucky. I always understood the timing belt coming off to mean the end of valves and pistons, but maybe not (or at least not in this case).

Yeah, that's what I don't get. Was this my 'get out of jail free' card? I'd say the rpms were just over 3krpms while cruising along when it happened. I wonder if it's in the FSM or stated by Subaru that the valves will clash?

Was this my 'get out of jail free' card? I wonder if it's in the FSM or stated by Subaru that the valves will clash?

It was, for sure.

They will interfere, I can attest to that.

Good to hear you came out okay. I once dropped a valve in a SBC while idling through a drive-thru....as soon as I heard the "TING", I shut it down. Pulled the head, replaced the valve and keeper, pressure checked everything....car made a 9.00 pass that weekend. Pure luck.

Good to hear you came out okay. I once dropped a valve in a SBC while idling through a drive-thru....as soon as I heard the "TING", I shut it down. Pulled the head, replaced the valve and keeper, pressure checked everything....car made a 9.00 pass that weekend. Pure luck.

I didn't do a leak down test but the comp test was enough to convince me that it's good to go. I left the gauge pressurized for about 20 seconds for each cyl. There was no pressure loss at all. In the past, I've seen where a valve wasn't seating while performing a comp test. The gauge would shoot up and down with each revolution of the crank. So I trust the results

These motors are probably capable of making nasty internal contact, but I'm just thinking out loud here... When the timing belt completely releases, the cams will pop to a resting point and stop. Even if they catch between the close side of the lobes I think the valves are going to be closed or very very close to it. Could be wrong there.

Jumping timing on the other hand, could cause contact, but the car would run like poop and hopefully give the driver a hint that he needs stop the car soon, before damage occurs.

Good to hear you came out okay. I once dropped a valve in a SBC while idling through a drive-thru....as soon as I heard the "TING", I shut it down. Pulled the head, replaced the valve and keeper, pressure checked everything....car made a 9.00 pass that weekend. Pure luck.

S.

You drive an 8 second 1/4 mile car on the street? Need proof for that one...

You drive an 8 second 1/4 mile car on the street? Need proof for that one...

It WAS a 5.61 1/8 mile car with a 540 CID BBC, for the record, but ran in the low nines on a 434 CID SBC, all motor....I retired and sold the car recently....but I'm sure the owner will hook you up with a race if YOU have something to brag about.

I'd drive down from Breckenridge and find out. IF n2 is lying by five or more seconds you might have a chance

That's why I get so pissed about dropping this much time and money into an import. Just to build a, god-help-me, reliable mid 12s car. Woopdee-friggin'doooo! I miss V8s. I don't miss the fuel consumption though.

And if dropping a valve counts as "interference" I did almost the same in a 429 ford motor once... but it was a bolt that was inadvertently dropped into an intake runner. The truck made it all the way from Greensboro NC. to Annapolis Md. drove around for a week and all the way back to Greensboro (but not quite all the way home ) before the bolt made its way through the intake valve and started mauling the piston. Let's just say I did NOT stop in time to fix that problem.

When the timing belt completely releases, the cams will pop to a resting point and stop. Even if they catch between the close side of the lobes I think the valves are going to be closed or very very close to it. Could be wrong there.

Jumping timing on the other hand, could cause contact, but the car would run like poop and hopefully give the driver a hint that he needs stop the car soon, before damage occurs.

That's my take as well.

You got lucky the belt came off the way it did as quickly as it did.

Home Depot bolts for timing assembly. Sweet

I stripped the threads for one of the idler pulleys when I did my SB swap.

Yep guys. I think 2phless has the right idea. They probably were close enough to being closed when the belt came free. I think out of the 4 cams, only the driverside intake had tention on it, as in the valves were in the open position. The other 3 seemed to be at the bottom of the lobes for the most part.

Jeff, imagine if aluminum blocks came with SS inserts from the factory. I was told by a buddy of mine that a lot of the aluminum parts on military planes have this, or at least they were like that when he was in the Navy. The Helicoils are SUPER strong. I don't think it'll be a problem again.

And yeah, the HD bolts are a NO-NO I won't be doing that anymore. In my defense though, it was late on a Sunday afternoon and nobody else was open. Of course I should've been more patient and fixed it with a thread insert to begin with and not the longer bolt.

It WAS a 5.61 1/8 mile car with a 540 CID BBC, for the record, but ran in the low nines on a 434 CID SBC, all motor....I retired and sold the car recently....but I'm sure the owner will hook you up with a race if YOU have something to brag about.

Not everyone is a blowhard, pal.

P.S. Bring a Hayabusa on spray, or stay home.

S.

So far you are the blown hard. Any chance that you have a time slip for this car?!?! And a pic going through the drive thru. YOU were the one who said it was going thru a drive-thru indicating a street driven car.

So far you are the blown hard. Any chance that you have a time slip for this car?!?! And a pic going through the drive thru. YOU were the one who said it was going thru a drive-thru indicating a street driven car.

Were you aware that you can replace the tensioner bracket that bolts to the block? Here's the part number. 13156aa062 It's about 25$

I forgot that it was a separate part until I began trying to repair it on the car. I took it off and then repaired it. Buying a new one could have saved me money and a headache Oh well, at least I know for future ref.

Such a sensible and quick-witted retort. I assume by your response that you have no proof to back up what you say. I put the ball back in your court that you originally served and not only did you miss but also you were lacking a racket.

In an earlier posts you are saying that cars in the low 9’s (potentially 8’s) drive on the street. The link below is a high 8 second car and I’d be willing to bet the only street time this car sees is on a trailer.

I am not saying that I can go faster, I am just calling ride5000’s bluff.

2mile, if you've never seen a mid 8 or low 9 street driven car, you have been living a sheltered life. I've built 3 for me personally. Do I make 100 mile trips with them? No. 93 octane? Hardly. Do they have A/C or cruise? No. They are a single-purpose automobile, designed to crack the ass of young punks like yourself that think 8-9 second cars aren't on the street.

P.S. You're not calling anyone's bluff by asking for a time slip... Anyone can whip one up in Photoshop. I don't have anything to prove to you, or anyone else....but if you're THAT naive, call (256) 538-7223, and ask Jason Collins (the track owner) about Steve Jordan's Black 88 coupe Mustang (now sold) with the Chevrolet drivetrain. Jeez.